A plant is running on 400 V, 50 Hz LT supply for 10 hours. The load comprises lighting load of 2.5kW @ 0.9 pf lagging on R-phase, heater load 5 kW @ UPF on Y-Phase and a 3-Phase SCIM drawing 5 kW @ 0.8 pf lagging. What is the total energy consumption by the loads?
A plant is running on 400 V, 50 Hz LT supply for 10 hours. The load comprises lighting load of 2.5kW @ 0.9 pf lagging on R-phase, heater load 5 kW @ UPF on Y-Phase and a 3-Phase SCIM drawing 5 kW @ 0.8 pf lagging. What is the total energy consumption by the loads? Correct Answer 125 units
Energy consumption:
Energy consumption is the use of power or energy of a system by making use of supply.
Energy = (Power x time) / 1000.
In electrical systems, Energy is calculated in kWh (kilo Watt-hours).
So, 1 unit of energy = 1kWh.
Power is in Watts
Time in hours.
Calculation:
All loads connected for 10 hrs
load comprises lighting load of 2.5kW @ 0.9 pf lagging on R-phase
Energy consumed on R phase = 2.5kW × 10hr = 25kWh = 25 units
heater load 5 kW @ UPF on Y-Phase
Energy consumed on Y phase = 5kW × 10hr = 50kWh = 50 units
3-Phase SCIM drawing 5 kW @ 0.8 pf lagging on B phase
Energy consumed on B phase = 5kW × 10hr = 50kWh = 50 units
Total energy consumption by the loads = 25 + 50 + 50 = 125 units